Rapid-Response Teams Fail to Prevent Cardiac Arrests or Deaths

by John Gever John Gever,Senior Editor, MedPage Today
December 02, 2008

Action Points

Explain to interested patients that rapid response teams are specialized groups of doctors and other professionals in hospitals, which focus on preventing cardiopulmonary arrest in high-risk patients.

Explain that this study found that neither death rates nor cardiopulmonary arrest rates declined significantly after these teams were introduced at one hospital.

Point out that this hospital may not be representative of hospitals elsewhere.

KANSAS CITY, Dec. 2 -- Rates of cardiopulmonary arrest or mortality did not decline significantly after facility-wide rapid-response teams went into action in a large Midwestern hospital, researchers here said.

Mortality rates at St. Luke's Hospital here declined by 4% (adjusted OR 0.95, 95% CI 0.81 to 1.11) after rapid-response teams were introduced in late 2005, reported Paul S. Chan, M.D., of the Mid America Heart Institute, and colleagues in the Dec. 3 issue of the Journal of the American Medical Association.

But after accounting for other changes occurring in the same time frame, including hospital quality-improvement programs and improved technologies, the adjusted odds ratio of 0.76 failed to reach statistical significance (95% CI 0.57 to 1.01, P=0.06.)

"Hundreds of hospitals around the country have invested significant financial and personnel resources in implementing rapid-response teams," Dr. Chan and colleagues said.

The teams are supposed to be called when patients are seen to be deteriorating markedly, triaging patients to the ICU or changing treatments as appropriate.

Their organization varies among institutions. At St. Luke's, they were led by nurses and included members from several disciplines. Physician input was available as needed.

On the basis of earlier studies finding that rapid deterioration frequently precedes cardiopulmonary arrest, rapid-response teams have been recommended as a strategy to reduce these events -- "despite the fact that limited published data support their effectiveness," Dr. Chan and colleagues said.

The "lack of robust outcomes" at St. Luke's suggests that randomized, controlled trials are needed to determine whether rapid-response teams really prevent cardiopulmonary arrests and deaths, the researchers added.

Dr. Chan and colleagues compared data on 24,193 patient admissions from January 2004 through August, 2005, before the rapid-response teams were implemented, with 24,978 admissions from January 2006 through August 2007.

After the teams were established, they were activated 376 times.

"To our knowledge, this is the longest follow-up study of a rapid-response team intervention with the greatest number of deaths and code events," the researchers said.

Mean hospital-wide rates for cardiopulmonary arrest codes declined from 11.2 per 1,000 admissions to 7.5 per 1,000 after the teams were instituted.

For non-ICU patients, the code rate declined significantly even after adjusting for potential confounding variables, the researchers found.

They calculated an adjusted odds ratio for non-ICU codes of 0.59 post- versus pre-intervention (95% CI 0.40 to 0.89). But the teams had no effect on codes among ICU patients (adjusted OR 0.95, 95% CI 0.64 to 1.43).

Dr. Chan and colleagues did not analyze mortality separately for ICU and non-ICU patients.

They reviewed charts for cases in which cardiopulmonary arrest or death occurred to examine whether underuse of teams or undertreatment may have contributed to the outcomes.

Among 24 cases ending in death in which rapid response teams were activated, the researchers determined that only two might have involved undertreatment.

Among 188 cases of arrest during the intervention period, the researchers found the teams were not called in 20 cases where it might have been reasonable to activate them. Sixteen of these patients died, representing potential underuse of teams.

But, the researchers determined that even if team activation had prevented all 18 of these deaths, the adjusted odds ratio for hospital-wide mortality would have been reduced only to 0.93 (95% CI 0.79 to 1.09).

For there to have been a statistically significant benefit, Dr. Chan and colleagues calculated, the teams would have had to prevent 80 additional deaths.

A limitation of the study was its reliance on formal coding of cardiopulmonary arrests in counting these events. The researchers suggested arrests may have been undercounted among patients triaged to the ICU by the rapid-response teams.

Because of the heightened clinical attention given to ICU patients, they may suffer cardiopulmonary arrest and die without formal arrest coding, Dr. Chan and colleagues said.

That could account for the lack of mortality benefit despite the apparent substantial decline in coded arrests found in the study, they speculated.

Alternatively, the researchers said, some patients for whom rapid response teams were called may have subsequently had do-not-resuscitate (DNR) orders instituted. Such patients then going into arrest would not receive codes.

Dr. Chan and colleagues said 46 of the 70 deaths associated with team activation occurred in patients with DNR orders instituted during or after team activation.

"These findings suggest that rapid-response teams may not be decreasing code rates as much as catalyzing a compassionate dialogue of end-of-life care among terminally ill patients," the researchers said.

That this was a single-hospital study also limits its generalizability, they said.

Issues for future research include the composition of rapid-response teams, the optimal triggers for activating them, and cost-effectiveness, the researchers recommended.

No external funding for the study was reported.

No potential conflicts of interest were reported.

Reviewed by Zalman S. Agus, MD Emeritus Professor University of Pennsylvania School of Medicine

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